Selective recognition of molybdenum(VI) from water by Mo(VI) oxy ion-imprinted particle as an adsorbent

The isonicotinic acid (4-picolinic acid) served as a functional monomer firstly to prepare Mo(VI) oxy ion-imprinted particle (Mo-IIP) by the surface metal ion imprinting technique with a sol-gel process on the surface of amino-silica, and TEOS acted as a cross-linker monomer. The prepared Mo-IIP was characterized and its proper selectivity recognition ability was investigated by single binding experiments comparing to Mo(VI) oxy ion non-imprinted particle (Mo-NIP). Furthermore, the reuse was carried out. A possible imprinting mechanism was put forward for the Mo-IIP. The binding process fitted well to the pseudo-second-order kinetic model, the Langmuir model, and the Weber-Morris model. The results suggested that a multi-step with the film and intraparticle diffusion process might dominate this chemical sorption for Mo(VI) binding onto Mo-IIP. The Mo-IIP exhibited selectivity for Mo(VI) with a remarkably high binding capacity 2171.46 mu mol g(-1), which was 7.6 times higher than that of the Mo-NIP. Such efficient selectivity might be due to the complexation ability of nitrogen atom in the 4-picolinic acid with supper memory sites after imprinting process. The excellent affinity and exclusive selectivity make the Mo-IIP become an potential material for Mo(VI) removal and concentration from the water environment. (C) 2013 Elsevier B.V. All rights reserved.